Non rubber - "rubber bands"

[KeepItSimpleStupid]

I'm looking for some decent bands that are say a #64, 3-1/2" x 1/4" but made out a better material such as Nitrile. It doesn't have to be Nitrile, it just has to be better than the standard rubber band.

 

[jpanhalt]

How much stretch do you need? Is the problem you are trying to solve the oxidation/degradation of the typical synthetic gum band or something else? I have have a little better durability with pure gum bands rather than with the synthetic bands.

For low stretch and durability, I have used sections taken from good quality inner tubes. Motorcycle and bicycle shops have been my source. A #64 size (diameter) has been easy to find. I would not use a typical HF innertube, as I have seen them dry rot in 6 months. "Butyl" rubber or neoprene seem OK. I have used those bands to retain such things as fuel tanks in models for 10 years with no problems.

Starting with sheet stock or strips, I have also made my own bands from neoprene sheet obtained from McMaster-Carr. I made some bungee cords for one of my models using a neoprene/kevlar reinforced rubber sheet. If you are near a small airport, bungee cords are still used on the landing gear of small aircraft. They will be a bit large for your application in all likelihood, but the rubber strands of which they are made are quite durable can also be used to fashion almost any size band you need. Just use multiple wraps and glue or tie the ends together. If there is a good hobby shop nearby, quality rubber strip sold for rubberband powered models can be used the same way. CA is a pretty good adhesive for rubber. You might remember the early commercials for Crazy Glue.

O-rings are another option, but they often have a joint in them that is a weak spot. Some O-ring rubbers are quite durable, but the elasticity may not be good enough for you.

John

 

[KeepItSimpleStupid]

Thanks John:

I was basically looking for a more durable rubber band. Elasticity and longevity would be the primary goals.
I like the inner tube idea.

So, CA glues rubber? What kind of overlap would you suggest?

When my father patched inner tubes he used to apply the supplied glue and then light it for a few seconds.

 

[jpanhalt]

I have done innertubes the same old way as your dad did. Pliobond (which contains neoprene monomer -- at least some versions did) will also work. I used CA plus a good knot on the bungee cords for my model. It has held up well over the years and been exposed to quite a bit of oily exhaust. Also available at hobby shops is a modified CA for "rubber" -- I suspect is just a slow CA modified with neoprene monomer. I got pretty much the same effect premixing some Pliobond with slow to medium CA, but that is not what I used for the bungee cords.

It is really important that the rubber be clean. I use MEK for that, a little abrasion and then MEK again. Adhesive for innertubes has a sulfur odor, and if you have it, I would consider it too. I believe the sulfur is to improve its adhesion. Many rubbers rely on sulfur compounds for polymerization. As for overlap, given a width of X, I wouldn't consider any overlap less than X. An overlap of 2X to 3X is probably better. Of course, if you rely simply on overlap, the ends will peel away from the base. That is why I used a knot and a tiny bit of CA

Any rubber that is stretched will degrade faster than one that is not stretched. So, if you decrease the amount that you stretch it, that will help. Bottom line, if an innertube will give enough stretch, that is what I would use. I only went to the alternatives because I wanted less stretch and because I did not have an open end to get a closed loop over.

John

Edit: For power drive belts, the overlapped ends are scarfed (tapered). That reduces the stress concentration at the ends of the overlap, but is probably a detail you can ignore.

 

[4pyros]

How about hair Bands from the women's department.
I use them to bundle small cables.

 

[KeepItSimpleStupid]

Wow! Where have you been?

 

[4pyros]

Wow! Where have you been?

Just taking care of life.

 

[KeepItSimpleStupid]

I know that feeling well. Glad your back.